Space heater

ABSTRACT

A space heater having a flame induced draft burner including a circular plate baffle provided with a central opening and radially extending fins with associated openings for imparting a rotary motion to an air and fuel mixture, and a combustion chamber arranged to receive mixed air and fuel from the plate baffle. The combustion chamber has a circular baffle member provided with radially extending fins and associated openings for retarding the speed of gases leaving the combustion chamber for ensuring complete combustion of the fuel and high heat transfer between the gases and the baffle member. In this manner, a portion of the baffle member is heated to a sufficient heat to assure spontaneous re-ignition in the event of a temporary interruption of fuel supply. A stackable sleeve having a tapered windshield pipe portion, tapered windshield increaser portion, and tapered exhaust pipe portion, is selectively mountable in symmetrical relation on the burner by frictional engagement with projecting members connected to the burner. The burner is supported by a plurality of legs, and if it is to be supported in the earth, stop members, or bearing plates may be provided on the legs for bearing against the earth surface.

United States Patent [191 Luft SPACE HEATER Alfred N. Luft, 3031 Regatta Dr., Sarasota, Fla. 33581 22 Filed: 'Dec.21, 1971 21 Appl. No.: 210,470

[76] Inventor:

Primary Examiner-William E. Wayner Assistant Examiner-William E. Tapolcai, Jr. Attorney, Agent, or FirmClarence A. OBrien; Harvey B. Jacobson [57] ABSTRACT A space heater having a flame induced draft burner Mar. 12, 1974 including a circular plate baffle provided with a cen tral opening and radially extending fins with associated openings for imparting a rotary motion to an air and fuel mixture, and a combustion chamber arranged to receive mixed air and fuel from the plate baffle. The combustion chamber has a circular bafi'le member provided with radially extending tins and associated openings for retarding the speed of gases leaving the combustion chamber for ensuring complete combustion of the fuel and high heat transfer between the gases and the baffle member. In this manner, a portion of the baffle member is heated to a sufficient heat to assure spontaneous re-ignition in the event of a temporary interruption of fuel supply. A stackable sleeve having a tapered windshield pipe portion, tapered windshield increaser portion, and tapered exhaust pipe portion, is selectively mountable in symmetrical relation on the burner by frictional engagement with projecting members connected to the burner. The burner is supported by a plurality of legs, and if it is to be supported in the earth, stop members, or bearing plates may be provided on the legs for bearing against the earth surface.

11 Claims, 6 Drawing Figures SPACE HEATER BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to a space heater, and more specifically to such a heater intended for use in orchards and the like. In particular, this invention relates to a flame induced draft oil burning heater.

2. Description of the Prior Art During periods of frost, it is necessary to protect orchards and similar crops from destruction by frost, and provide heat in or on construction sites. It is known in this regard to use various types of space heaters to generate heat in the area around the crops in order to prevent such frost destruction. Among the known agricultural heating systems are those in which fuel lines are run to various points in the area to be heated to attach heaters thereto. The fuel used is generally light oil or gas. Since these heaters are used only during low temperature periods, it is desirable to provide structure which may be easily removable from the site and stored in a minimum of space when not in use. Furthermore, because these heaters are subjected to severe elements, they must be so constructed as to withstand such elements with a minimum of maintenance and should be designed such that the re-ignite spontaneously in the event of a temporary interruption of the fuel supply. In addition, concern with air pollution in recent years has added the further requirement that such heaters be low to no in emission of pollutants.

The known orchard heaters and the like generally spray a fuel into a stack-like pipe with holes around the periphery, where it is intended to mix with air and emerge from the stack and pass directly into the atmosphere. These known arrangements result in inefficient combustion of fuel with a resulting loss of heat and very high emissions of smoke, noxious gas, and unburned fuel. This unburned fuel deposits on foliage, and can result in the killing of trees and other vegetation. Furthermore, they usually leak at the bottom, soaking the earth with fuel which prevents replanting in the particular area until the earth has been replaced.

In the case of construction sites, emissions from the known heaters cause oily deposits on surrounding surfaces and soak into flammable materials, creating fire hazards.

In addition, it is not desirable to use fuel oil as heavy as US. grade No. 2, or No. 2 diesel, in such heaters due to emissions, and clogging and coking. Further, the known burners for such fuel require a motor driven fan or draft inducer to facilitate clean combustion.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a space heater, and particularly an orchard heater, in which more complete combustion of the fuel is achieved. It is also an object of the present invention to provide such a heater which may be constructed without moving parts or complicated ignition systems, but will provide for automatically re-igniting the fuel-air mixture following temporary fuel interruptions. Initial ignition of the fuel-air mixture is by manual means.

These and other objects are achieved according to the present invention by providing a space heater having a burner with means for mixing air and fuel and imparting a rotary motion thereto, and a combustion chamber arranged to receive mixed air and fuel from the mixing means and having means for retarding the speed of gases leaving the combustion chamber for assuring complete combustion of the fuel and high heat transfer between the gases and the baffle member for spontaneous re-ignition upon temporary interruption of fuel. I

In a preferred embodiment of the present invention the combustion chamber is a cylindrical tube and is connected to a mixing means also in the form of a cylindrical tube and provided with a plurality of inlet vanes arranged angularly with respect to the cylindrical tube and defining a plurality of peripheral openings for passing air tangentially therethrough and thereby imparting a circular motion to the air. The cylindrical tube with vanes are connected to the lower end of the combustion chamber and having a pair of spaced end portions. The lower end portion is a plate with a center hole to provide means for inserting the oil line. The upper end portion is a plate having a hole concentric with its diameter and surrounded by a plurality of vanes arranged angular thereto. The lower portion of the upper plate has a cylindrical baffle of predetermined length arranged concentrically thereto and whose inside diameter coincides with the outside diameter of the angular vanes. The upper portion of the upper end plate has a short cylindrical baffle, of the same diameter as the lower cylindrical baffle, and which ends in a hollow member in the shape of a frustrum of a right circular cone. This hollow member increases the velocity of mixed air and fuel passing therethrough for establishing a violent mixing in-the combustion chamber portion of the heater. The peripheral openings, baffles, and hollow member define a flow path that requires air entering through the peripheral openings to pass around the cylindrical baffle, and through the plate baffle and hollow member. A nozzle means is arranged concentrically in the cylindrical baffle for spraying fuel into the air flow path. A distributor plate with three equally spaced arms is mounted on the nozzle means to assure concentricity of the nozzle with respect to the cylindrical baffle, and for forcing air outward as it passes the distributor plate and create a slight reverse current in the center of the flow to maintain flame position. A plurality of legs are attached to the lower plate for supporting and anchoring the heater spaced from a surface. If this surface is earth, particularly sandy soil, stop members are advantageously provided on the legs for limiting the distance the legs may be inserted into the earth and preventing a shifting of the heater.

The combustion chamber of a preferred embodiment of the present invention is provided with an outlet spaced from the upper end plate, with the means for retarding the exhaust gases being a baffle member covering the combustion chamber outlet and provided with angled fins and associated openings.

The space heater according to the present invention is further provided with means selectively mountable on the burner for providing a windshield and exhaust pipe therefor. This providing means may be a tapered sleeve having a tapered windshield pipe portion, a tapered windshield increaser portion, and a tapered exhaust pipe portion. Means are provided for centering this member on the burner by frictionally engaging a wall portion of the tapered windshield pipe portion. This means is preferably an engagement of the tapered windshield increaser portion with the upper end of the combustion chamber and a plurality of projections connected to the burner for maintaining the tapered sleeve in symmetrical relation on the burner.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a space heater according to the present invention.

FIG. 2 is a sectional view taken generally along the line 22 of FIG. 1.

FIG. 3 is a sectional view taken generally along the line 3-3 of FIG. 2.

FIG. 4 is a sectional view taken generally along the line 4-4 of FIG. 2.

FIG. 5 is a fragmentary sectional view taken generally along the line 55 of FIG. 2.

FIG. 6 is a perspective view showing a burner for a space heater according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. I of the drawings, a space heater 10 according to the present invention has a means 12 which is a tapered sleeve 13 having a tapered windshield pipe portion 14, a tapered windshield increaser portion 15, and a tapered exhaust pipe portion 16. Space heater 10 further has a plurality of legs 18 provided with stop members 20 for abutting against a surface 21 on which heater 10 is resting and functioning as bearing plates. Surface 21 would be an earth surface when heater 10 is used as a, for example, orchard heater. A supply line 22 may be connected to a known pressurized source of fuel, such as No. 2 fuel oil. This fuel source is ofa type well known in the art and is not shown in the drawings. When heater It) is to be used individually or in series as a heat source at construction sites and the like, a suitable, known valve (not shown) may be inserted in supply line 22.

As can best be seen from FIGS. 2 and 6 of the drawings, heater It) has a flame induced draft burner, specifically an oil burner, 24 with means 26 for mixing air and fuel and imparting a rotary motion thereto, and a fire or combustion chamber 28 arranged to receive mixed air and fuel from mixing means 26. Combustion chamber 28 has a cylindrical wall 29 which may be constructed from a material such as cast iron or steel. Combustion chamber 28 further has a means 30 for retarding the speed of gases leaving chamber 28 for assuring complete combustion of the fuel.

Means 26 has a circular plate 32 provided with a plurality of vanes 34 arranged perpendicularly thereto and defining a plurality of peripheral openings 36 (FIG. 3) for passing air tangentially therethrough. Plate 32 and vanes 36 form a housing 37 having a pair of spaced end portions 38, 40. A cylindrical baffle 42 is arranged concentrically in housing 37, and extends from a point 44 between end portions 38, d0 to a point 46 at the one housing end portion 38. A hollow member 48 formed in the shape of a frustrum of a right circular cone has a cylindrical base 50 dimensioned to mate with cylindrical baffler 42 and connected to end portion 38 at point 46 for functioning as an air condenser and increasing the velocity of mixed air and fuel passing therethrough for establishing a violent mixing in combustion chamber 28.

A circular plate baffle 52 is arranged between hollow member 43 and cylindrical baffle 42 and connected to both of same, and is provided with an opening 54 (FIG.

4) which is concentric with respect to cylindrical baffle 42, and radially extending fins 56with associated openings 58 (FIG. 3) surrounding concentric opening 54 for imparting the rotary motion to mixed air and fuel passing therethrough. The peripheral openings 36, baffles 42, 52, and hollow member d8 define a flow path that requires air entering through peripheral openings 36 to pass around cylindrical baffle 42, and through plate baffle 52 and hollow member 48.

A nozzle means 60 having a nozzle 61 is arranged concentrically in cylindrical baffle 42 adjacent plate baffle 52 for spraying fuel into the flow path. Nozzle 61 is of the conventional nature with, for example, an 80 spray. Nozzle means 60 has a nozzleadapter 62 on which air inlet distributor plate 64 is mounted, as can best be seen from FIG. 3. Fuel oil is supplied at, for example, lOO psi in line 22. Plate 64 has three equally spaced arms 65 so as to form an air passage therearound. The air is forced outward as it passes plate 64, and a slight reverse current is created in the center of the flow. Nozzle means 60 may also be provided with a suitable, known check valve (not shown) for preventing air from entering the system through the nozzles and cause fuel to leak out therefrom in those instances when at least one nozzle means 60 is at a different elevation than at least one other nozzle means 60 during periods when there is no pressure supplied to a string of heaters 10.

Plate 32 covers end portion 40. A wall 68 is provided therein for defining an opening 70 for permitting supply line 22 to pass therethrough and be connected to nozzle means 60. A known clamp 71 fastens line 22 to plate 32 and holds plate 64 and nozzle means 60 rigid and centered in baffle 42.

Combustion chamber 28 is provided with an outlet '72 and an inlet 74 spaced from outlet 72 and connected to end 33. Means 3d has a circular baffle member 78 (FIG. 5) covering outlet 72 and provided with a center portion 79, fins 30 and associated openings 82. Member '73 functions as an exhaust mixer. A, for example, heat retaining element 83 may be attached to portion 79. Baffle 78 may be constructed from, for example, a stainless steel or other suitable material for withstanding high temperatures to which it is constantly subjected during operation. Element 83 becomes very hot and assures re-ignition in the event of temporary interruption of fuel supply.

A means 84 is mounted on wall 29 of burner 24 for frictionally engaging portion M of tapered sleeve 13 for centering same on burner 24. This means 84 is preferably three projections 66 equally spaced about the circumference of wall 29.

Peripheral openings 36 and fins are preferably arranged to create a counterclockwise flow of air and/or air-fuel mixture in the direction of flow. Fins 56 of baffle plate 52 are arranged so as to create a clockwise flow when looking in the direction of flow.

In operation, a flame induced draft causes a flow of air through peripheral openings 36, under cylindrical baffle 42, and through baffle plate 52 and hollow member 48 into combustion chamber 28. Fuel is injected into the flowing air as it approaches baffle plate 52. The resultant violent flow of the fuel-air mixture in combustion chamber 28 results in an even distribution thereof which achieves more efficient combustion. Heater may be started by applying a flame from a known torch 5 to the fuel-air mixture in combustion chamber 28 as through holes 88 (FIG. 3) provided in plate 32. There may be, for example, three holes 88. Baffle member 78 retards the speed of the combustion gases leaving the combustion chamber. This will result in the gases remaining in the chamber for a longer period of time and, thus, being completely consumed. A heater in which a burner 24 is, for example, approximately 10 inches in diameter and approximately 13 inches in length is capable of putting out approximately 1 12,000 BTU per hour.

Sleeve 13 may be easily removed from burner 24 and stacked with other sleeves 13 for convenient storage. Burner 24 may be left in place, or it may be disconnected from the fuel source and conveniently stored with legs 18 removed from sockets 90 (FIG. 2).

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

What is claimed as new is as follows: 4

l. A space heater comprising, in combination:

a. means for mixing fuel and a flame induced flow of air and imparting a rotary motion thereto, and including a circular plate provided with a plurality of vanes arranged perpendicular thereto and defining a plurality of peripheral openings for passing air tangentially therethrough; and

b. a combustion chamber arranged to receive mixed air and fuel from the mixing means, and having means for retarding speed of gases leaving the combustion chamber for assuring complete combustion of the fuel, said circular plate and vanes partially forming a housing having a pair of spaced end portions, and said mixing means further including a cylindrical baffle arranged concentrically in said housing and extending from a point between the housing end portions to a point at one housing end portion, and a hollow member in the shape of a frustrum of a right circular cone having a cylindrical base dimensioned to mate with said cylindrical baffle and arranged adjacent thereto at said point at one housing end portion for increasing the velocity of mixed air and fuel passing therethrough and establishing a violent mixing in said combustion chamber.

2. A structure as defined in claim 1, wherein said the cylindrical baffle, and through the plate baffle and hollow member.

3. A structure as defined in claim 2, wherein said mixing means further includes an air inlet distributor plate having arms and arranged concentrically in said cylindrical baffle, and nozzle means also arranged concentrically in said cylindrical baffle adjacent said plate baffle for spraying fuel into the flow path and supporting said air distributor plate, the arms of said air inlet distributor plate centering said nozzle means in said cylindrical baffle.

4. A structure as defined in claim 3, wherein said mixing means further includes a plate covering the other of the housing end portions and having a wall defining an opening for permitting a supply line for said nozzle means to pass therethrough, and a plurality of legs attached to said plate for supporting and anchoring the burner spaced from a surface.

5. A structure as defined in claim 4, wherein a stop member is provided on said legs for preventing said legs from settling into earth.

6. A structure as defined in claim 1, wherein said combustion chamber is provided with an outlet and an inlet spaced therefrom and connected to said cylindri-.

cal baffle, and said means for retarding is a baffle member covering the combustion chamber outlet and provided with fins in associated openings.

7. A structure as defined in claim 1, wherein said mixing means and combustion chamber form a flame induced draft burner, and the space heater further comprises means selectively mountable on said burner for providing a windshield and exhaust pipe. I

8. A structure as defined in claim 7, wherein the providing means is a stackable tapered sleeve, and means are mounted on said burner for frictionally engaging a wall portion of said tapered sleeve and centering same.

9. A space heater, comprising, in combination:

a. nozzle means for spraying fuel under pressure and' providing a flame arranged for inducing a flow of air;

b. means for mixing the fuel and induced flow of air and imparting a rotary-motion thereto; and

c. a combustion chamber arranged to receive mixed air and fuel from the mixing means, and having means for retarding speed of gases leaving the combustion chamber for assuring complete combustion of the fuel, the nozzle means, mixing means, and combustion chamber forming a burner means for inducing a draft solely by flame induction, and mixing means including a plurality of vanes arranged about the circumference of a circle and defining a plurality of peripheral openings for passing air tangentially therethrough, a cylindrical baffle arranged concentrically within said vanes, and a hollow member in the shape of a frustrum of a right circular cone having a base dimensioned to mate with said cylindrical baffle and arranged adjacent thereto for increasing the velocity of mixed air and fuel passing therethrough and establishing a violent mixing in said combustion chamber.

Ml). A structure as defined in claim 9, wherein space heater further comprises means removably mountable on the burner for providing a windshield and exhaust pipe, the providing means being a stackable tapered sleeve, and means are mounted on said burner for fric- 3,796,209 7 8 tionally engaging a wall portion of said tapered sleeve said means for retarding is a baffle member covering and centering same. the outlet and provided with fins and associated open- 11. A structure as defined in claim 10, wherein said ings.

combustion chamber is provided with an outlet and 

1. A space heater comprising, in combination: a. means for mixing fuel and a flame induced flow of air and imparting a rotary motion thereto, and including a circular plate provided with a plurality of vanes arranged perpendicular thereto and defining a plurality of peripheral openings for passing air tangentially therethrough; and b. a combustion chamber arranged to receive mixed air and fuel from the mixing means, and having means for retarding speed of gases leaving the combustion chamber for assuring complete combustion of the fuel, said circular plate and vanes partially forming a housing having a pair of spaced end portions, and said mixing means further including a cylindrical baffle arranged concentrically in said housing and extending from a point between the housing end portions to a point at one housing end portion, and a hollow member in the shape of a frustrum of a right circular cone having a cylindrical base dimensioned to mate with said cylindrical baffle and arranged adjacent thereto at said point at one housing end portion for increasing the velocity of mixed air and fuel passing therethrough and establishing a violent mixing in said combustion chamber.
 2. A structure as defined in claim 1, wherein said mixing means further includes a circular plate baffle arranged between said hollow member and said cylindrical baffle and connected to both of same, and provided with an opening concentric with respect to said cylindrical baffle and radially extending fins with associated openings surrounding the concentric opening for imparting the rotary motion to mixed air and fuel passing therethrough, the peripheral openings, baffles, and hollow member defining a flow path that requires air entering through the peripheral opening to pass around the cylindrical baffle, and through the plate baffle and hollow member.
 3. A structure as defined in claim 2, wherein said mixing means further includes an air inlet distributor plate having arms and arranged concentrically in said cylindrical baffle, and nozzle means also arranged concentrically in said cylindrical baffle adjacent said plate baffle for spraying fuel into the flow path and supporting said air distributor plate, the arms of said air inlet distributor plate centering said nozzle means in said cylindrical baffle.
 4. A structure as defined in claim 3, wherein said mixing means further includes a plate covering the other of the housing end portions and having a wall defining an opening for permitting a supply line for said nozzle means to pass therethrough, and a plurality of legs attached to said plate for supporting and anchoring the burner spaced from a surface.
 5. A structure as defined in claim 4, wherein a stop member is provided on said legs for preventing said legs from settling into earth.
 6. A structure as defined in claim 1, wherein said combustion chamber is provided with an outlet and an inlet spaced therefrom and connected to said cylindrical baffle, and said means for retarding is a baffle member covering the combustion chamber outlet and provided with fins in associatEd openings.
 7. A structure as defined in claim 1, wherein said mixing means and combustion chamber form a flame induced draft burner, and the space heater further comprises means selectively mountable on said burner for providing a windshield and exhaust pipe.
 8. A structure as defined in claim 7, wherein the providing means is a stackable tapered sleeve, and means are mounted on said burner for frictionally engaging a wall portion of said tapered sleeve and centering same.
 9. A space heater, comprising, in combination: a. nozzle means for spraying fuel under pressure and providing a flame arranged for inducing a flow of air; b. means for mixing the fuel and induced flow of air and imparting a rotary motion thereto; and c. a combustion chamber arranged to receive mixed air and fuel from the mixing means, and having means for retarding speed of gases leaving the combustion chamber for assuring complete combustion of the fuel, the nozzle means, mixing means, and combustion chamber forming a burner means for inducing a draft solely by flame induction, and mixing means including a plurality of vanes arranged about the circumference of a circle and defining a plurality of peripheral openings for passing air tangentially therethrough, a cylindrical baffle arranged concentrically within said vanes, and a hollow member in the shape of a frustrum of a right circular cone having a base dimensioned to mate with said cylindrical baffle and arranged adjacent thereto for increasing the velocity of mixed air and fuel passing therethrough and establishing a violent mixing in said combustion chamber.
 10. A structure as defined in claim 9, wherein space heater further comprises means removably mountable on the burner for providing a windshield and exhaust pipe, the providing means being a stackable tapered sleeve, and means are mounted on said burner for frictionally engaging a wall portion of said tapered sleeve and centering same.
 11. A structure as defined in claim 10, wherein said combustion chamber is provided with an outlet and said means for retarding is a baffle member covering the outlet and provided with fins and associated openings. 